Method of automatically detecting a test result of a probe zone of a test strip

ABSTRACT

Embodiments of a method and/or apparatus for automatically detecting a test result of a probe zone of a test strip are provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for detecting a test result ofeach probe zone of a test strip, and more particularly to a method fordetecting a test result of each probe zone of a test strip via an imagecapturing/processing technology.

2. Description of the Prior Art

Over the past decade, there has been an increased need and demand foranalysis of various biological specimens, for purposes ranging frompregnancy testing to drug analysis. Considerable time and effort hasbeen expended by way of devising systems and analytic techniques toensure reliable testing and accurate results.

Moreover, with increasing rise in the use of abuse-type drugs, the needfor detecting and identifying those drugs and their metabolites isbecoming more important. With this need, many more tests are required tomonitor the use of abuse-type drugs.

Thin layer chromatography (TLC) screening procedures for detecting drugsin urine require the careful preparation of a test specimen and then askillful application of that test specimen to a plate placed into adeveloping chamber. Once the plate is removed from the chamber anddried, it is sprayed with visualization reagents. Location and color ofspots are compared with those of known standards. Qualitative judgementsare made as to the presence of various drugs in the unknown sample. Theprocedure is tedious, time consuming and requires skilled personnel tointerpret the results.

The EMIT (Enzyme Multiplied Immuno-chemical Test) procedure is asemi-quantitative immuno-assay for drugs of abuse in biological fluids.The laboratory test requires trained technicians to perform and theequipment necessarily costs several thousands of dollars.

The RIA (Radio-Immuno-Assay) procedure is a sensitive and quantitativelaboratory procedure for detecting drugs of abuse. The variousimmunochemicals are labeled with radioactive compounds and requirespecial care in their use and disposal. A license is required from thegovernment to use this laboratory procedure because of the presence ofradioactive materials. The GLC (Gas-Liquid Chromatography) procedure canprovide the highest degree of accuracy in drug analysis. However, thenecessary equipment is expensive and the procedure is complicated.Consequently, highly trained personnel are required for its use.

Each of these well-known procedures requires skilled technicians andrelatively sophisticated equipment. Consequently, the testing procedureis necessarily expensive.

However, the increase of drug abuse has increased a need for new methodsof analyzing drug residues in physiological fluid. A drug abuse testpaper for testing the presence or absence of drugs in a fluid specimencollected from a test subject is developed. The drug abuse test paper issensitive to specific drugs of abuse in the fluid specimen collectedfrom the test subject, and has a lack of color change indicating apositive response to a specific drug of abuse in the fluid specimen, andrepresenting the specific drug of abuse present therein. While, a colorchange indicates a negative response to the specific drug of abuse,representing the specific drug of abuse absent in the fluid specimen.

An introduction of various color patterns occurring on the drug abusetest strip under various testing situations is provided herein. Firstly,referring to FIG. 1A, which is a schematic top view of the drug abusetest strip 10 prior to testing the fluid specimen collected from thetest subject. The drug abuse test strip 10 is blank and no color patterndisplayed thereon prior to testing the fluid specimen. The dotted lines11 through 16 respectively represent a probe zone of the drug abuse teststrip 10. The top probe zone of the drug abuse test strip 10corresponding to the site of dotted line 11 displays a color change inresponse to the fluid specimen, which is used to indicate whether theamount of the fluid specimen is sufficient to move through all probezones of the drug abuse test strip 10 by capillary action. The colorline displayed on the top probe zone is called control line. The otherprobe zones of the drug abuse test strip 10 corresponding to the sitesof dotted lines 12 through 16 respectively display a color change inresponse to a respective drug of abuse presenting in the fluid specimen.The color lines displayed on these probe zones are called target lines.

Referring to FIG. 1B, which shows a color pattern of the drug abuse teststrip 10 having no color change occurring in the top probe zonerepresented by the dotted line 11, which is under a testing situationthat the amount of the fluid specimen is not sufficient to assure thefluid specimen moves through all probe zones of the drug abuse teststrip 10. Therefore, in accordance with the color pattern consisting ofsolid lines 14 through 16 shown in FIG. 1B, the drugs of abusepresenting in the fluid specimen cannot completely detected andidentified. Referring to FIG. 1C, which shows a color pattern of thedrug abuse test strip 10 having only one color line 11 displayed in thetop probe zone of the drug abuse test strip 10. It means the top probezone has a positive response in response to the fluid specimen. Theamount of the fluid specimen is sufficient to pass through all probezones on the drug abuse test strip 10. All other probe zones representedby the dotted lines 12 through 16 have positive responses to the fluidspecimen, and all drugs of abuse corresponding to these probe zonespresent in the fluid specimen. Referring to FIG. 1D, which shows a colorpattern of the drug abuse test strip having color lines 11, 12 and 15displayed in the top probe zone and some other probe zones of the drugabuse test strip 10, which means the top probe zone 11 has a positiveresponse to the fluid specimen, indicating the amount of the fluidspecimen is sufficient, and the probe zones represented by the colorlines 12 and 15 have a negative response to the fluid specimen,indicating that the absence of the drugs of abuse corresponding to thesetwo probe zones in the fluid specimen. On the contrary, the probe zonesrepresented by the dotted lines 13, 14 and 16 have a positive responseto the fluid specimen, indicating that the presence of the drugs ofabuse corresponding to these three probe zones in the fluid specimen.

The top probe zone on the drug abuse test strip 10 has a positiveresponse in response to the specimen fluid, a color response occurs.That is, the control line 11 would display thereon. One of the otherprobe zones of the drug abuse test strip 10 has a positive response inresponse to a specific drug of abuse of the fluid specimen, there is nocolor response occurs on the probe zone. It means the specific drug ofabuse is present in the fluid specimen, and there is a highly content ofthe specific drug of abuse in the fluid specimen. However, one of theother probe zones of the drug abuse test strip 10 has a negativeresponse in response to a specific drug of abuse of the fluid specimen,a color response, i.e. target line, is displayed on the probe zone. Thecolor shade of the target line can be used to monitor the content of thespecific drug of abuse or even represents absence of the specific drugof abuse in the fluid specimen. The color shade of each of the targetlines 12 to 16 is inversely proportional to the content of a specificdrug of abuse to be detected in the fluid specimen. The higher thecontent of the specific drug of abuse is, the lighter the color shade ofthe target line is. The content of the specific drug of abuse isinversely proportional to the color intensity, i.e. the shade of color,of the target line. It is difficult to visually determine what certainlevel of the color shade of the target line representing the presence ofthe specific drug of abuse to be detected. Therefore, it is notconvincing for concluding whether the test subject has used abuse-typedrugs.

Accordingly, it is an intention to provide means capable of detectingand identifying the presence or absence of drugs of abuse in a fluidspecimen, which can overcome the problems of the conventional methods.

SUMMARY OF THE INVENTION

It is one objective of the present invention to provide a method ofautomatically detecting a test result of a probe zone of a test strip,which reads a bar code pattern corresponding to the test strip to obtainsetting values of target lines of the test strip, and in accordance withthe setting values, determines respective test results of the targetlines of the test strip contacting with a test liquid.

It is another objective of the present invention to provide a method ofautomatically detecting a test result of a probe zone of a test strip,which utilizes an image capturing device associated with an userinterface to capture images of a color pattern of the test strip and acorresponding bar code pattern, then decoding the bar code pattern toobtain setting values of target lines of the test strip, and therebydetermining the respective test results of the target lines, thendirectly displaying the test results on the user interface for viewing.

It is still another objective of the present invention to provide amethod of automatically detecting a test result of a probe zone of atest strip, which utilizes an image capturing/processing technologyassociated with an application for image analysis to automaticallydetermine respective test results of target lines of the test strip. Themanual operation is eliminated and the detection time is shortened.

In order to achieve the above objectives of this invention, the presentinvention provides a method of automatically detecting a test result ofa probe zone of a test strip. A scanning object including a bar code anda plurality of test strips is provided. The bar code is placed in apredetermined position on the scanning object and the test strips arearranged in sequence on the scanning object not overlapped with the barcode. Each of the test strips has a color pattern including a controlline and a plurality of target lines arranged in sequence on the teststrip from one end to the other end thereof. The control line and eachof the target lines respectively correspond to a probe zone of the teststrip. Scanning the scanning object to read a bar code pattern of thebar code and capture images of the test strips. Decoding the bar codepattern of the bar code to obtain information of types of the teststrips and thereby a plurality of mapping tables of setting valuesversus positions of the target lines on the test strip. Each mappingtable corresponds to one of the test strip based on the type of the teststrip, and each setting value of the mapping table corresponds to theposition of one target line of the test strip. Calculating a colorresponse of one target line of the test strip based on the image of thetest strip. Comparing the color response of the target line of the teststrip with the setting value corresponding thereto derived from themapping table corresponding to the test strip so as to determine whetherthe target line has a positive test result or a negative test result.

The present method detects a bar code corresponding to a test strip toobtain the type of the test strip. And, obtaining respective settingvalues of target lines of the test strip in accordance with a mappingtable of the setting values versus the target lines, which is correlatedto the type of the test strip. Thereby, determining respective testresults of the target lines of the test strip contacting a test liquidby comparing the respective color responses of the target lines with therespective setting values. Hence, the present invention provides anautomatic, rapid and accurate method to determine the test result of theprobe zone of the test strip.

BRIEF DESCRIPTION OF THE DRAWINGS

The objectives and features of the present invention as well asadvantages thereof will become apparent from the following detaileddescription, considered in conjunction with the accompanying drawings.

FIG. 1A to FIG. 1D shows schematic top views of a known drug abuse teststrip under various testing situations;

FIG. 2 is a schematic configuration of a user interface utilized in thepresent invention;

FIG. 3A and FIG. 3B are schematic top views of scanning objects of thepresent invention;

FIG. 4 is a flow chart of the present method according to an embodimentof the present invention;

FIG. 5 is a schematic view of a format of a bar code utilized in theembodiment of the present invention;

FIG. 6 is a schematic top view of an image of a test strip having acolor pattern displayed thereon; and

FIG. 7 is a diagram of pixel value versus pixel position established inaccordance with one scan line selected from the image of the test stripof FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a method of automatically detecting atest result of a probe zone of a test strip, which utilizes an imagecapturing device, such as a scanner, to capture an image of a colorpattern having a control line and a plurality of target lines of thetest strip, for example a drug-abuse type test paper, and a bar codepattern of a bar code corresponding to the test strip. Decoding the barcode pattern to obtain the type of the test strip, and thereby a mappingtable of setting values versus respective target lines of the test stripcorrelated to is obtained. The type of the test strip determines thetest strip detect what kinds of specific components contained in a testliquid. Each setting value represents a threshold of a color response ofone of the target lines having a positive test result in response to aspecific component of the test liquid. Calculating the color response ofthe target line of the test strip in accordance with the image of thecolor pattern of the test strip, and comparing the color response of thetarget line with the setting value corresponding thereto derived fromthe mapping table to determine whether the target line has a positive ornegative test result. Then, the test result is directly displayed on auser interface associated with the image capturing device. A user canview the test result of each of the target lines of the test strip fromthe display of the user interface.

FIG. 2 is a schematic configuration of the user interface associatedwith the image capturing device utilized in the present invention. Animage preview window 20 is displayed on a right side portion of the userinterface. The image preview window 20 displays preview images ofscanning objects. FIG. 3A and FIG. 3B are schematic top views of thescanning objects of the present invention. The scanning object 30 ofFIG. 3A includes a bar code 31 and a test strip 32 having a colorpattern including a control line and a plurality of target linesarranged in sequence on the test strip 32 from one end to the other endthereof. The control line has a color change in response to a testliquid tested by the test strip 32 and each of the target linesrepresents a probe zone having a color change in response to a specificcomponent in the test liquid. The scanning object 33 of FIG. 3B includesa bar code 34 and a plurality of test strips 35, 36 and 37. The bar code34 is placed in a predetermined position on the scanning object 33 andthe test strips 35, 36 and 37 are arranged in sequence on the scanningobject 33 not overlapped with the bar code 34. The test strips 32, 35,36 and 37 shown in FIG. 3A and FIG. 3B can be the drug abuse test paper10 of FIG. 1. And, the test liquid can be a kind of biological specimencollected from a test subject, such as blood, urine, sweat, and saliva.The user can directly select the preview image of one of the scanningobjects on the image preview window 20 to execute a normal scan.Alternately, the user can select the preview images of several scanningobjects on the image preview window 20 at one time. The selection orderof the preview images would be stored.

A first region for displaying image analysis results 33 is displayed ona left portion of the user interface and used for displaying an imageanalysis result under a normal scan for the selected image. The displayof the image analysis result includes a diagram 24 of image intensityversus image position of the target lines of each of the test strips ofthe scanning object and a data table 25 of image intensity versus imageposition of the target lines. The data table 25 also includes an “ID”column for showing an ID number reading from the bar code labeled on thescanning object and a “Name” column corresponding to a test subjectwhose biological specimen is tested by the test strips of the scanningobject. The user can key in the name of the test subject in the “Name”column. In the data table 25, each of the test strips of the scanningobject is given an item number in accordance with the sequence of thetest strips arranged in the scanning object, wherein each of the teststrips only detects one specific component contained in the test liquid.The data table 25 also has a column “(Judgment/Control)” displaying testresults of the target lines and control lines of the test stripscontacting with the test liquid. “Judgment” displays the test result ofthe target line of the test strip and “Control” displays the test resultof the control line of the test strip. The test result “+/or −” of thetarget line and control line of the test strip is automaticallydisplayed on the data table 25 by the present method for decoding thebar code pattern of the bar code labeled on the scanning object toobtain the setting value of the target line and comparing the colorresponse of the target line with the setting value to determine the testresult. Besides, there are several selection buttons (Target 7, Target8, Target 9, Target 10, Target 11, Target 12) displayed on a top portionof the first region for displaying image analysis results 23. The orderof the selection buttons corresponds to the order of selection of thepreview images on the image preview window 20. The user can click one ofthe selection buttons to switch the displaying of the first region fordisplaying image analysis result 23.

A second region for displaying function buttons 26 is displayed belowthe first region for displaying image analysis results 23 on the userinterface. The function buttons include a preview button (Preview), ascan button (Scan), an auto button (Auto), a print result button (PrintResult), a print report button (Print Report) and an auto print button(Auto Print). The preview button provides an image preview scan functionand the scan button provides a normal scan function for the selectedpreview image. The auto button provides a normal scan for the whole pageof preview images displayed on the preview window 20. The print resultbutton (Print Result) provides a function for printing out the imageanalysis result under the normal scan for the selected preview image.The print report button (Print Report) provides a function for printingout an image under the normal scan for the selected preview image andthe image analysis result thereof. The auto print button (Auto Print)provides a function for print out images under the normal scan for thewhole page of preview images displayed on the image preview window 20and the image analysis results thereof.

FIG. 4 is a flow chart of the present method according to an embodimentof the present invention. Initially, at step 40, providing a scanningobject having a bar code and a plurality of test strips arranged insequence thereon. The bar code is placed at a predetermined position onthe scanning object and the test strips are arranged in sequence on thescanning object not overlapped with the bar code. Each of the teststrips has a color pattern including a control line and a plurality oftarget lines arranged in sequence on the test strip from one end to theother end thereof. The control line has a color change in response to atest liquid tested by the test strip and each target line representing aprobe zone having a color change in response to a specific component inthe test liquid. The scanning object can be the scanning object 30 or 32of FIG. 3A and FIG. 3B. The test strips can be classified to varioustypes in accordance with how many kinds of specific components in thetest liquid can be detected by the test strip. The bar code can have aone-dimensional bar code pattern, for example, as shown in FIG. 5,including a “start” bar pattern, a first group of bar patternscorresponding to types of the test strips on the scanning object, eachbar pattern of the first group sequentially corresponding to the type ofone of the test strips, a plurality of second groups of bar patterns,each second group of bar patterns sequentially corresponding to one ofthe test strips, and each bar pattern of the second group sequentiallycorresponding to the position of one of the target lines of the teststrip, a third group of bar patterns corresponding to an identificationnumber of the scanning object, and a “stop” bar pattern. Each of the barpatterns of the bar code has a constant code length and is consisted ofbars and spaces.

At step 41, scanning the scanning object to read the bar code pattern ofthe bar code and capture images of the test strips with the imagecapturing device with a charged-coupled device having R, G, B channelsdisposed in parallel thereon. Each of the R, G, B channels includes aplurality of sensor cells, and each sensor cell corresponds to a pixelposition. Alternately, the present invention can utilize acharge-coupled device with a single channel, such as a charge-coupleddevice with a red channel, a charge-coupled device with a green channelor a charge-coupled device with a blue channel. Then, at step 42,decoding the bar code pattern of the bar code to obtain information oftypes of the test strips and thereby a plurality of mapping tables ofsetting values versus positions of the target lines on the test strip.Each mapping table corresponds to one of the test strips based on thetype thereof reading from the bar code, and each setting value of themapping table corresponds to one specific component to be detected byone target line of the test strip. The setting value is a threshold of acolor response of the target line having a positive test result inresponse to the specific component. When a test strip of type I isdetected by reading the bar code, a mapping table I as shown in thefollowing correlated to is obtained.

TABLE I Position of target line 1 2 3 4 5 Setting value 50 30 60 55 70

The mapping table I lists positions of the target lines of the teststrip of type I and the respective setting values. Herein, for example,the test strip of type I can detect five specific components in the testliquid, therefore the mapping table I lists the positions of five targetlines of the test strip of type I and their respective setting values.The positions of the target lines are based on the sequence of thetarget lines on the test strip of type I. Hence, the setting value ofeach target line of the test strip can be obtained by reading the barcode and further by the mapping table correlated to.

Following, at step 43, calculating a color response of one of the targetlines of the test strip based on the image of the test strip. FIG. 6 isa schematic view of the image of the color pattern of the test strip 10can be placed on the scanning object. The color pattern of the teststrip 10 includes a control line 11 and several target lines 12 to 16.Selecting at least one scan line L–L′ from the image, the scan line L–L′is perpendicular to the image of the control line 11 and the targetlines 12 to 16. A diagram of pixel value versus pixel position for thecontrol lines 11 and the target lines 12 to 16 is thus established inaccordance with the scan line L–L′, see FIG. 7. The diagram of FIG. 7shows three curves respectively representing the relationship of pixelvalue of R, G and B versus pixel position. Determining a color responseR of the target line, such as the target line 13, from one of the threecurves, for example the curve in blue pixels/or the combination of thethree curves and in accordance with a formula (I):R={(T−C)/(A−C)}×100%  (I),wherein T represents an average pixel value of a section of pixelscorresponding to the image of the target line 13, C represents anaverage pixel value of a section of pixels corresponding to the image ofthe control line 11, and A represents an average pixel value of a firstsection A₁ of pixels and a second section A₂ of pixels corresponding tothe images of the base of the test strip 10 respectively adjacent to theimage of the target line 13.

Then, at step 44, comparing the color response of the target line of thetest strip with the setting value corresponding thereto derived from themapping table corresponding to the test strip. At step 45, when thecolor response of the target line of the test strip is not smaller thanthe setting value, determining the target line has a positive testresult (+) in response to one specific component in the test liquid andrepresenting the specific component presents in the test liquid. Whenthe color response of the target line of the test strip is less than thesetting value, determining the target line has a negative test result(−) in response to the specific component and representing the specificcomponent is absent in the test liquid. The test results for the targetlines of the test strip determined by the present method are directlydisplayed on the data table 25 of the user interface of FIG. 2.

The present method detects the bar code corresponding to the test stripto obtain the type of the test strip. And, obtaining respective settingvalues of the target lines of the test strip in accordance with amapping table of the setting values versus the target lines, which iscorrelated to the type of the test strip. Thereby, determiningrespective test results of the target lines of the test strip contactingwith the test liquid by comparing the respective color responses of thetarget lines with the respective setting values. Hence, the presentinvention provides an automatic, rapid and accurate method to determinethe test result of the probe zone of the test strip. The manualoperation is eliminated and the detection time is shortened.

The embodiment is only used to illustrate the present invention, notintended to limit the scope thereof. Many modifications of theembodiment can be made without departing from the spirit of the presentinvention.

1. A method of automatically detecting a test result of a probe zone ofa test strip, comprising: providing a scanning object including a barcode and a plurality of test strips, said bar code placed in apredetermined position on said scanning object and said test snipsarranged in sequence on said scanning object not overlapped with saidbar code, each said test strip having a color pattern including acontrol line and a plurality of target lines arranged in sequence onsaid test strip from one end to the other end thereof, and said controlline and each said target line respectively corresponding to a probezone of said test strip; scanning said scanning object to read a barcode pattern of said bar code and capture images of said test strips;decoding said bar code pattern of said bar code to obtain information oftypes of said test strips and thereby a plurality of mapping tables ofsetting values versus positions of said target lines on one said teststrip, each said mapping table corresponding to one said test stripbased on the type of said test strip; calculating a color response ofone said target line of one said test strip based on the image of saidtest strip; and comparing the color response of said target line of saidtest strip with said setting value corresponding thereto derived fromsaid mapping table corresponding to said test strip so as to determinewhether said target line has a positive test result or a negative testresult.
 2. The method of claim 1, wherein the color response of saidtarget line of said test strip is calculated in accordance with aformula (I):R={(T−C)/(A−C)}×100% (I), wherein T represents on average pixel value ofa section of pixels corresponding to the image of said target line, Crepresents an average pixel value of a section of pixels correspondingto the image of said control line, and A represents an average pixelvalue of a first section of pixels and a second section of pixelscorresponding to the images of the base of said test strip respectivelyadjacent to the image of said target line.
 3. The method of claim 2,wherein said color response R of said target line of said test strip iscalculated based on the image of said test strip in red pixels.
 4. Themethod of claim 2, wherein said color response R of said target line ofsaid test strip is calculated based on the image of said test strip ingreen pixels.
 5. The method of claim 2, wherein said color response R ofsaid target line of said test strip is calculated based on the image ofsaid test strip in blue pixels.
 6. The method of claim 2, wherein saidcolor response R of said target line of said test strip is calculatedbased on the image of said test strip in average pixels values of red,green, and blue pixels.
 7. The method of claim 1, wherein said bar codehas a one-dimensional bar code pattern, including: a first group of barpatterns corresponding to types of said test strips, each said barpattern sequentially corresponding to the type of one said test strip; aplurality of second groups of bar patterns, each said second group ofbar patterns sequentially corresponding to the position of one saidtarget lines of said test strip; and a third group of bar patternscorresponding to an identification number of said scanning object. 8.The method of claim 7, wherein each said bar pattern of said bar codehas a constant code length and consists of bars and spaces.
 9. Themethod of claim 1, wherein said control line has a color change inresponse to a test liquid tested by said test strip and each said targetline has a color change in response to a specific component in said testliquid.
 10. The method of claim 9, wherein each said setting value ofsaid mapping table corresponds to one said specific component to bedetected by one said target line of said test strip.
 11. The method ofclaim 10, wherein when the color response of said target line of saidtest strip is not smaller than said setting value, determining saidtarget line having a positive test result in response to said specificcomponent in said test liquid and representing said specific componentpresent in said test liquid; when the color response of said target lineof said test strip is less than said setting value, determining saidtarget line having a negative test result in response to said specificcomponent and representing said specific component absent in said testliquid.
 12. The method of claim 9, wherein said test liquid includes abiological fluid collected from a subject.
 13. The method of claim 12,wherein said biological fluid is selected from a group consisting ofblood, urine, sweat and saliva.
 14. The method of claim 1, wherein saidtest strip includes a drug abuse test paper.
 15. An apparatus,comprising: a scanning object comprising a bar code and a plurality oftest strips, wherein said bar code has a one-dimensional bar codepattern, including; a first group of bar patterns, at least one of saidbar patterns corresponding to at least one type of a group of objects; aplurality of second groups of bar patterns, at least one of said secondgroup of bar patterns corresponding to a set of setting values for saidat least one type of group of objects; and a third group of bar patternscorresponding to an identification number of said scanning object;wherein at least some of said setting values correspond to at least someof said plurality of test strips.
 16. The apparatus of claim 15, whereinsaid one-dimensional bar code pattern has a constant code length andconsists of bars and spaces.